<template>
	<view class="u-wrap">
		<view class="">
			<view class="u-search-box">
				<view class="u-search-inner">
					<u-search placeholder="请输入搜索关键字" v-model="keyword" @search="search"></u-search>
				</view>
			</view>
		</view>
		<view class="u-menu-wrap">
			<scroll-view scroll-y scroll-with-animation class="u-tab-view menu-scroll-view" :scroll-top="scrollTop">
				<view v-for="(item,index) in categoryList" :key="item.id">
					<!-- <view class="u-line-1 navTitle">{{item.name}}</view> -->
					<view class="u-tab-item" :class="[current==index ? 'u-tab-item-active' : '']"
						:data-current="item.id" @tap.stop="swichMenu(item.id, index)">
						<view class="u-line-1">{{item.name}}</view>
					</view>
				</view>
			</scroll-view>
			<scroll-view scroll-y class="right-box" @scrolltolower="tolower">
				<view class="page-view">
					<view class="class-item">
						<view class="item-container" v-if="goodsList.length > 0">
							<navigator class="thumb-box u-p-20" v-for="(goods, index) in goodsList" :key="index"
								:url="`/pages/goods/show?id=${goods.id}`">
								<image class="item-menu-image" :src="goods.cover_url"></image>
								<view class="item-menu-name">{{goods.title}}</view>
							</navigator>
						</view>
						<view v-else>
							<u-loadmore :status="status" class="u-text-center" />
						</view>
					</view>
				</view>
			</scroll-view>
		</view>
	</view>
</template>

<script>
	export default {
		data() {
			return {
				tabbar: [],
				categoryList: [], //tab列表数据
				goodsList: [],
				scrollTop: 0, //tab标题的滚动条位置
				current: 0, // 预设当前项的值
				menuHeight: 0, // 左边菜单的高度
				menuItemHeight: 0, // 左边菜单item的高度
				keyword: '',
				category_id: '',
				page: 1,
				status: 'loadmore',
				isLast: false,
				nexPage: null,
			}
		},
		onLoad() {
			this.getGoodsData()
			console.log(this.status)
		},
		computed: {

		},
		methods: {
			search() {
				this.goodsList = []
				this.getGoodsData();
			},

			// 获取商品数据
			async getGoodsData() {
				if (this.isLast) return;

				const params = {
					category_id: this.category_id,
					title: this.keyword,
					page: this.page
				}
				const res = await this.$u.api.goodsList(params);
				this.goodsList = [...this.goodsList, ...res.goods.data]
				this.tabbar = res.categories;
				this.nexPage = res.goods.next_page_url
				console.log('res', res, this.goodsList)
				let categoryList = []
				this.tabbar.map((e) => {
					e.children.map(el => {
						categoryList.push(el)
					})
				});
				this.categoryList = categoryList;
			},
			// 点击左边的栏目切换
			async swichMenu(id, index) {
				this.category_id = id;
				this.page = 1;
				this.goodsList = []
				if (index == this.current) return;
				this.current = index;
				this.getGoodsData();
				if (this.goodsList.length === 0) this.status = 'nomore'
				console.log(this.status, this.goodsList.length, this.category_id)

				// 如果为0，意味着尚未初始化
				if (this.menuHeight == 0 || this.menuItemHeight == 0) {
					await this.getElRect('menu-scroll-view', 'menuHeight');
					await this.getElRect('u-tab-item', 'menuItemHeight');
				}
				// 将菜单菜单活动item垂直居中
				this.scrollTop = index * this.menuItemHeight + this.menuItemHeight / 2 - this.menuHeight / 2;
			},
			// 获取一个目标元素的高度
			getElRect(elClass, dataVal) {
				new Promise((resolve, reject) => {
					const query = uni.createSelectorQuery().in(this);
					query.select('.' + elClass).fields({
						size: true
					}, res => {
						// 如果节点尚未生成，res值为null，循环调用执行
						if (!res) {
							setTimeout(() => {
								this.getElRect(elClass);
							}, 10);
							return;
						}
						this[dataVal] = res.height;
					}).exec();
				})
			},
			// 底部下拉加载
			tolower() {
				if (!this.nexPage) {
					this.$u.toast('到底了')
					return;
				};
				this.page = this.page + 1;
				this.getGoodsData()
			}
		}
	}
</script>

<style lang="scss" scoped>
	.u-wrap {
		height: calc(100vh);
		/* #ifdef H5 */
		height: calc(100vh - var(--window-top));
		/* #endif */
		display: flex;
		flex-direction: column;
	}

	.u-search-box {
		padding: 18rpx 30rpx;
	}

	.u-menu-wrap {
		flex: 1;
		display: flex;
		overflow: hidden;

		.navTitle {
			width: 100%;
			padding: 10rpx;
			font-weight: 550;
			background-color: #2979ff;
			color: #fff;
		}
	}

	.u-search-inner {
		background-color: rgb(234, 234, 234);
		border-radius: 100rpx;
		display: flex;
		align-items: center;
		padding: 10rpx 16rpx;
	}

	.u-search-text {
		font-size: 26rpx;
		color: $u-tips-color;
		margin-left: 10rpx;
	}

	.u-tab-view {
		width: 200rpx;
		height: 100%;
	}

	.u-tab-item {
		height: 110rpx;
		background: #f6f6f6;
		box-sizing: border-box;
		display: flex;
		align-items: center;
		justify-content: center;
		font-size: 26rpx;
		color: #444;
		font-weight: 400;
		line-height: 1;
	}

	.u-tab-item-active {
		position: relative;
		color: #000;
		font-size: 30rpx;
		font-weight: 600;
		background: #fff;
	}

	.u-tab-item-active::before {
		content: "";
		position: absolute;
		border-left: 4px solid $u-type-primary;
		height: 32rpx;
		left: 0;
		top: 39rpx;
	}

	.u-tab-view {
		height: 100%;
	}

	.right-box {
		background-color: rgb(250, 250, 250);
	}

	.page-view {
		padding: 16rpx;
	}

	.class-item {
		margin-bottom: 30rpx;
		background-color: #fff;
		padding: 16rpx;
		border-radius: 8rpx;
	}

	.item-title {
		font-size: 26rpx;
		color: $u-main-color;
		font-weight: bold;
	}

	.item-menu-name {
		font-weight: normal;
		font-size: 24rpx;
		color: $u-main-color;
	}

	.item-container {
		display: flex;
		flex-wrap: wrap;
	}

	.thumb-box {
		width: 50%;
		display: flex;
		align-items: center;
		justify-content: center;
		flex-direction: column;
		margin-top: 20rpx;
		box-sizing: border-box;
	}

	.item-menu-image {
		width: 120rpx;
		height: 120rpx;
	}
</style>
